Printing press



S. J. MOLLET July 19, 1932.

PRINTING PRES S Filed Feb. 28, 1929 7 Sheets-$heet l ATTORNEY July 19,1932. s. J. MOLLET PRINTING PRESS Filed Feb. 28, 1929 7 Sheets-Sheet 2\N AN ATTORNEY July 19, 1932. 5 J MOLLET 1,867,859

PRINTING PRESS FiledwFeb. 28, 1929 7 Sheets-Sheet 3 I44 lpo INVENTORATTORNEY July 19, 1932. 5. J. MOLLET PRINTING PRESS Filed Feb. 28, 19297 Sheets-Sheet 4 INVENTOR Y SW11 W B aamflq Ac ATTORNEY July 19, 1932.S.-J.IMOLLET 1,867,359

PRINTING PRESS Filed Feb. 28, 1929 7 Sheets-Sheet 5 INVENTOR F 14-. aATTORNEY v we A BY July 19, 1932. s. J. MOLLET PRINTING PRESS Filed Feb.28, 1929 '7 Sheets-Sheet 6 ATTORNEY (a July 19, 1932. 3 J, MQLLET1,867,859

PRINTING PRESS Filed Feb. 28, 1929 7 Sheets-Sheet 7 In IE m //5 INVENTORF1 E3. BY MENU? a s- H ATTORNEY illl Patented July 19, 1932 UNI-TEDSTATES SAMUEL J. MOLLET, F MASSILLON, OHIO PRINTING PRESS Applicationfiled February 28, 1929.

This invention relates to printing presses and more particularly to aprinting press adapted for printing large signs such as employed forroad-side advertising purposes.

The invention has for its object to provide a printing press havingmeans for rapidly and accurately printing upon a surface of a large areaand having means independent of the printing cylinders for feeding largesheets or plates between the printing cylinders and delivering them fromthe machine.

A further object is to provide means for accurately positioning eachsheet as it is deliveredto the press, together with means independent ofthe cylinders for automatically feeding the sheets in a straight linebetween the printing cylinders.

A further object is to provide a printing press having automaticpositioning and feeding means which is capable of printing upon sheetsor plates varying greatly in length and Width.

A further object is to provide a stop device for positioning sheets in aposition to be engaged by the grippers of the sheet feeding or conveyingmeans which is automatically shifted by the conveying means to aninoperative position simultaneously with the engagement of the sheet bythe grippers and which is automatically returned'to operativeposiactuated by a moving part of the press and which is'adjustable sothat the time of the release of the stop mechanismimay be regulated inaccordance with the length of the sheet.

A further object is to provide anautoinatic gripper mechanism in whichthe gripper arms are held both in grippingand releasing position bymeans of a spring actuated toggle, the operation of the arms in eitherdirection being accomplished by a trip device which acts to shift thepivotof the toggle past its dead center position.

A further object is to provide a feed mechanism consisting of endlessconveyorchains mounted for'movement past opposite ends of Serial No.343,523.

the cylinders and connected by cross :bars carrying grippers forengaging the sheets and to provide adjustable supports for thehorizontal upper run of the chains by means of which the grippers may beaccurately'ad-v just-ed and maintained inhorizontal alinement with thebight of the printing cylinders:

A further object is toprovidemeansfor' supporting the sheet intermediateitssides and ends after it has passed between thenoylinders, the sheetsupporting means being so: constructed as not to interfere withthepassage of the gripper cross bars.v

Vdith the above and other objects in:vie\v;. the invention may. be saidto comprise the printing press as illustrated in-the accompanyingdrawings hereinafter described and particularly set forth in theappended claims, together with such variations andiimodificationsthereof as will be apparentto one skilled in the art to which theinvention appertains.

Reference should be hadto the accompany.- ing drawings forming a partof. this specie fication in which Figure 1 is a perspective view of aprinting press embodying the invention looking toward the feed-inendthereof:

Fig. 2 is a section taken on the lineindicated at 2-2 in Fig. 3, lookingin the direction indicated by the arrows.

Fig. 3 is a longitudinal vertical. section taken on the line indicatedati33 in Fig.2 looking in the direction indicatedby the arrows.

Fig. 4 is a fragmentary side elevation of. the end of the machine atwhich the Printing cylinders are located.

Fig. 5 is a section takenon the line indicated at 5-5 in Fig. 4, lookingin the direc ing the inking mechanism, the cam being shown in theposition which it occupies when the inking mechanism is in operatingposition.

Fig. 10 is a detail view of the cam and roller shown in Fig. 9, showingthe cam and roller in the positions which they occupy in holding theinking mechanism out of engagement with the form cylinder.

Fig. 11 is a plan view of the stop device for positioning sheets forengagement with the conveying means by which they are moved between theprinting cylinders.

Fig. 12 is a vertical section taken immediately in front of the stopdevice shown in Fig. 11 and showing the stop device in elevation.

Fig. 13 is a section taken on the line inclicated at 1313 in Fi 12,looking in the direction indicated by the arrows.

Fig. 14 is a section taken on the line indicated at 14-14 in Fig. 12,looking in the direction indicated by the arrows.

Fig. 15 is a side elevation of the gripper device with a portion of theside frame broken away to show the gripper actuating means.

Fig. 16 is a section taken on the line indicated at 16-16 in Fig. 17looking in the direction indicated by the arrows.

Fig. 17 is a section taken on the line indicated at 17-17 in Fig. 15looking in the direction indicated by the arrows.

Fig. 18 is a side elevation showing the gripper actuating cam and thetrip roller on the frame with which the cam engages.

Fig. 19 is a longitudinal section showing the grippers and forward endof the sheet between the printing cylinders.

Fig. 20 is a fragmentary section taken axially through the formcylinder.

Fig. 21 is a transverse section through one of the chain guides taken onthe line indicated at 2121 in Fig. 3, looking in the direction indicatedby the arrows.

Fig. 22 is a fragmentary longitudinal sec tion at the discharge end ofthe machine showing one sprocket and conveyor chain in side elevation.

Fig. 23 is a detail plan view of the treadle by means of which the formcylinder may be shifted out of engagement with the compression cylinder,together with the retaining latch for holding the treadle in its lowerposition. .1

Referring to the accompanying drawings, the main elements of the machineof the present invention are an elongated table 1, along which thesheets are moved during the printing operation, a form cylinder 2 abovethe level at which the sheets are supported and a compression cylinder 3immediately beneath the form cylinder, the two cylinders being supportedone above the other between suitable standards 4.

Only one pair of printing cylinders is shown in the accompanyingdrawings, but it is to be understood that, when desired, a number ofprinting cylinders may be arranged in a row along the length of thetable to suecessively print upon a sheet, fed along the table.

The sheets are fed through the printing cylinders by means of conveyorchains 5 which are supported at opposite sides of the table inhorizontal guides 6 which are dis posed at the level of the bight of thecylinders. A roller table 7 is placed at the front end of the conveyortable 1 and has rollers positioned at the level of the chains so thatsheets may be pushed along a table 7 to position their forward edgesimmediately in front of the cylinders on the table 1.

For moving the sheets between the cylinders, suitable gripper devicesindicated generally by the numeral 8 are supported by the chains andextend across the space between the chains and in order to enable thegripper devices to pass between the cylinders, the gripper deivces arespaced apart a distance equal to the circumference of the compressioncylinder and the compression cylinder has an axially extendingperipheral recess 9 in which the gripper supporting bars are positionedduring their passage between the cylinders.

(lo-operating with the gripper devices, there is a stop device indicatedgenerally by the numeral 10, which is positioned immediately in front ofthe printing cylinders and which serves to position each sheet as it isfed to the machine for engagement by the grippers. During the printingoperation, the sheets are moved in a straight line at the peripheralspeed of the form cylinder from the front to the rear end of the table1, the ink or paint being transferred from the form on the form cylinderto the surface of the sheet as the sheet passes between the cylinders.

The present invention resides in various features of construction andvarious mechanisms employed by which the machine is enabled to rapidlyand accurately printupon fiat surfaces of large size.

The form cylinder As best shown in 1, 19 and 20, the form cylinder 2 ismounted upon a transverse shaft ll'and consists of a cyl ndrical bodyportion 12 formed of wood mounted upon a plurality of spiders 13 on theshaft 11. The spiders are preferably formed in two halves and have themating hub portions 14 thereof clamped together upon the shaft 11. Discs15 are keyed to the shaft 11 beyond the ends of the cylinders 2 and apair of large gear wheels 16 are connected to the discs 15 by means ofbolts 17 which pass through arcuate slots 18 in the discs. By looseningthe bolts 17, the cylinder may be adjusted angularly with respect to thegear wheels so as to accurately register the form with the surface to beprinted upon. The peripheral portion of the cylinder 2 has a recess orgap 19 extending from one end of the cylinder to the other whichregisters with the recess 9 of the compression cylinder 3 duringrotation of the cylinders.

Upon th periphery of the cylinder 2, there is secured a form 20preferably composed of a rubber composition secured upon a fabricbacking 21, the form is secured to the cylinder at one end by suitablemeans such as nails 22 shown in Fig. 19 and at its opposite end thefabric backing 21 extends beyond the end of the composition body of theform and is wrapped about a square shaft 23 which is positioned in theslot or gap 19 of the cylinder and extends from one end of the cylinderto the other.

The shaft 23 is rotatably mounted and forms a reel to wind up the fabric21 and draw the form tightly about the cylinder, suitable means beingprovided for locking the shaft 23 after the form is tightened on thecylinder. Any suit-able letters and designs may be formed in intaglio onthe form 20, as indicated at 24 in Fig. 1. The ink or paint is appliedto the smooth surface of the form around the recessed portions coatingthe sheet on all portions of its surface which contact with the cylinderexcept those portions which register with the recessed letters,characters or designs on the form.

Driving mechanism for cylinders and 00aoey or chains The printingcylinders and the conveyor chains have a common drive which is shown inFigs. 2 and 3 of the drawings. Fixed to the shaft of the compressioncylinder 3, and positioned beneath the gear wheels 16, are gear wheels25 which mesh with the gear wheels 16. The pitch circles of the gearwheels 16 and 25 coincide with the cylindrical surfaces of the cylindersso that the cylinders rotate with equal peripheral speeds.

In order to feed the sheets between the cylinders at a speed equal tothe peripheral v speeds of the cylinders, the conveyor chains 5 must bedriven at a speed equal to the peripheral speed of the cylinders. Theconveyor chains are supported at the front and rear ends of the table bymeans of sprockets 26 and 27 which support the chains in alinement withthe guides 6. The lower runs of the chains 5 are below the compressioncylinder 3, the chains guided over the sprockets 28 and 29 positioned tothe front .i and rear of the cylinder 3.

v to a short longitudinal shaft 35 which opera-tes suitable reductiongearing in the gear casing 36 which drives a, transverse shaft 37, whichhas fixed thereto adjacent its ends gears 38 which mesh with the gears25. The gears 38 also mesh with gears 39 fixed to a transverse shaft 40to which the sprockets 29 are attached. The gears 25, 38 and 39 are soproportioned that the conveyor chains are driven at a linear speed equalto the peripheral speed of the printing cylinders.

[airing mechanism As best shown in Figs. 3 and 7, the inking mechanismwhich applies a uniform coating of ink or paint to the surface of theform 20 M is mounted for movement bodily toward and from the rear sideof the cylinder 2 and is supported on a carriage 41 which is mounted forsliding movement upon supporting brackets 42 which are attached to therear edges of the standards 4. Each of tl e brackets 42 has a horizontalguideway 43 which extends in a direction longitudinally of the table 1and the carriage 41 is movable between stop shoulders 44 formed by therear edges of'the standards 4 projecting above the brackets 42 andshoulders 45 at the rear ends of the brackets, the carriage beingpressed toward and normally held against the shoulders 45 by means ofcoil springs 46 interposed between the shoulders 44 and the rear end ofthe carriage. A supporting frame 47 for the inking mechanism isadjustably mounted upon the carriage 41, the frame 47 being slidable onthe carriage 41 between front and rear stop shoulders 48 and 49 andbeing adjustable by means of front and rear screws 50 adjustable in theframe 47 and having rounded heads 51 engageable with the shouders 48 and49.

The heads 51 are adapted to receive a-suitable tool for turning thescrews and, by ad justing the screws, the frame 47 may be adjustedforwardly or rearwardly on the carriage 41. J ournaled in the frame 47adjacent the front end thereof, there is a transverse shaft 52 which isin horizontal alinement with the shaft 11 supporting the form cylinder.The shaft 52 carries an inking roller 53, the surface of which liesclosely adjacent to the surface of the form on the cylinder 2. The shaft52 also has fixed thereto gears 54 which mesh with the large gears 16 ofthe form cylinder. The pitch circles of the gears 16 coincide with thecylindrical surface of the form and the pitch circles of the gears 54coincide with the cylindrical surface of the roller 53 so that theperipheral speed of the roller 53 is equal to the peripheral speed ofthe form cylinder. Adjacent the top there of, frame 47 has horizontalslots 55 forming guideways at the ends thereof and in these guidewaysare slidably mounted bearing blocks 56 which are pressed rearwardly bycompression coil springs 57 which are inter posed between the frame 47and the forward faces of the blocks. The rear faces of the blocks areengaged by the forward ends of screws 58 which have threaded engagementin openings in the frame 47 and these screws are provided at their rearends with hand wheels 59 by means of which the screws may be advanced tomove the blocks 56 forwardly in opposition to the springs 57. Atransverse shaft 60 is j ournaled in the bearing blocks 56 and thisshaft carries a roller 61 which cooperates with the roller 53, theroller 61 serving to apply a coating of ink or paint to the surface ofthe roller 53 which in turn applies a coating to the form 20. In theends of the frame 17 above the shaft 60, there are mounted short shafts62 which support scrapers 63 which engage the shoulders of the roller 61to remove any paint or ink thereon.

Beneath the slots 55 are horizontal guide slots (i i in which areslidably mounted bearing blocks 65', the front faces of which bearagainst compression coil springs 66 seated in the frame 47 and the rearfaces of which are engaged by the forward ends of screws 6? which areprovided at their rear ends with hand wheels 68. By adjusting the screws67 the bearing blocks 65 may be adjusted toward or from the forward endsof the slots 64. Journaled in the bearing blocks 65, there is atransverse shaft 69 which carries a roller 70 which co-operates with theroller 61 to apply a coating of ink or paint thereto. Gears 71 fixed tothe shaft 60 mesh with the gears 54: on the shaft 52 and gears 72 fixedto the shaft 69 mesh with the gears 71 on the shaft 60. The pitchcircles of the gears 71 and 72 coincide with the cylindrical surfaces ofthe rollers 61 and 70 so that the peripheral speed of the three inkingrollers 53, 61 and 69 are equal. The lower portion of the roller 70 dipsinto paint or ink contained in a pan 7 3 supported beneath the roller, aportion of this paint or ink adheres to the surface of the roller 70,which applies a coating to the roller 61, which applies a coating to theroller 53, which in turn coats the form on the cylinder 2.

It will be apparent that the clearance be tween the surface of the form20 and the surface of the roller 53 may be adjusted by means of thescrews 50, that the clearance between the roller 61 and the roller 53may be adjusted by the screws 58 and that the clearance between therollers 70 and 61 may be ad justed by means of the screws 67. Thethickness of the coating transferred from one roll er to the next andfrom the large roller 53 to the form 20 is dependent upon the amount ofclearance between the rollers and by means of the adjustments providedby the screws 50, 58, and 67, a very uniform coating may be applied toeach of the rollers and to the form and the thickness of this coatingcan be very accurately regulated.

The ink pan 73 ext nds across the frame beneath the roller 70 a d hasattached to the bottom thereof a longitudinal bar 74 which has upwardlyextending dowel pins 7 5 which fit in sockets in an overhanging portionof the frame 47 to hold the pan against sliding or tilting movements.The ends of the bar 74 p are supported upon swinging blocks 7 6 whichare connected to the frame 47 by vertical pivots 77. The blocks 76 haverearwardly extending arms 78 which carry latch pins 79 which areyieldingly pressed downwardly by springs 80 and which engage in socketsformed in the frame d? to hold the blocks 7 6 in supporting position. Byreleasing the latch pins 79, the blocks 76 may be swung outwardly frombeneath the cross bar 7% to permit the pan to be lowered and removedfrom the frame. The ink pan may thus be quickly and easily removedwhenever it is desired to clean or replace the pan as for instance whenan ink or paint of a difierent color is to be employed. If desired,several pans may be provided and one pan substituted for another whendesired.

Throw-out mechanism In order to enable the operator to instantly stopthe printing operation, as for instance, when the sheet being printedupon is mis alined with respect to the form, mechanism is provided forshifting the form cylinder out of printing position and means is alsoprovided by which the ink? mechanism may be simultaneously renderedinoperative. The throw-out mechanism is shown in 3 to 10 of thedrawings.

As shown in Fig. 4., the shaft 11 of the form cylinder 2 is journaled atits ends in bearing blocks 81 which are slidably mounted in verticallydisposed guide openings or bearing vindows 82 in the side standards 4.Each of the bearing blocks 81 is provided with a tubular internallythreaded extension 83 which receives the upper threaded end of avertically disposed supporting rod 84, a lock nut 85 being provided onthe rod which engages the lower end of the tubular extension to securethe rod in adjusted position therein. The lower end of each supportingrod 8% is threaded and extends into an internally threaded tubularextension 86 of an eccentric member 87 which is supported upon aneccentric 88. .tach of the eccentrics 88 rotatably mounted on a stubshaft 89 which is clamped to a plate 90 secured to the standard 4. Thesupporting rod 8 1- has lock .ut 91 thereon which engages with .he upperend of the tubular ext nsion 86 of the eccentric mem her to secure therod in adjusted position with respect to the eccentric member. Coilsprings 92 are interposed between a washer 93 seated on the bottom ofeach of the bearing windows 82 and a nut 9son the upper threaded endportion of the supporting rods The coil springs 92 are of sufiicientstrength to support the major portion of the weight of the form cylinder2 and the tension of these springs may be adjusted by adjusting the nuts94.

The lifting of the form cylinder out of printing position isaccomplished by rotating the eccentrics 88 and to accomplish thisrotation, each of the eccentrics 88 has formed integrally therewith agear 95 which is operated by means of a gear segment 96 in meshtherewith. The gear segments 96 are formed on the rear ends of levers 97which are pivoted at 98 to the standards 4 on opposite sides of themachine. The lever 97 has an upwardly extending arm 99 to the upper endof which is pivoted a rod 100 which extends forwardly from the armthrough an opening in a vertical flange 101 of a bracket 102 attached tothe side standard 4.

The rod 100 is guided for endwise movement in the flange 101 and the arm99 is normally held in its forward limit of movement by a coil spring103 which is interposed between the flange 101 and the shoulder 104formed on the rod 100 near the rear end thereof. The spring 103 servesto normally hold the segment 96 in its lowermost position in whichposition the eccentric 88 is in a position to hold the form cylinder 2in printing position. The pivots 98 are located intermediate the ends ofthe levers 97 and the forward ends of the levers are adjacent theforward edges of the standards 4. To the forward ends of the levers 97are pivoted downwardly extending links 105 which are pivoted at theirlower ends to arms 106 fixed to a transverse rock shaft 107 journaled inthe standards 4. Adjacent the ends thereof, the shaft 107 hasfixed'thereto forwardly extending arms 108 to which are attacheddepending links 109 which are pivoted at their lower ends to levers 110.The levers 110 are connected at their forward ends to the standards 4 bypivots 111 and are provided at their forward ends with treadles 112.\Vhen the operator steps on either of the treadles 112, the forward endsof the levers 97 are rocked downwardly and the gear segments 96 areswung upwardly rotating the eccentrics 88 in a direction to lift theform cylinder. An operator standing upon either side of the machine atthe forward end thereof may instantly shift the form roller out ofprinting position during passage of the sheet between the cylinders bystepping on one of the treadles 112.

In order to retain the form cylinder in its inoperative position, meansis provided for automatically latching the lever 112 in loweredposition. This latching means comprises a horizontally swinging latch113 which is connected by a vertical pivot 114 to a bracket 115 attachedto the forward edge of the adjacent standard 4. Each latch member 113has an inwardly projecting latch shoulder 116 which is engaged by thelever 110 in its downward movement to swi'ng the latch member 113outwardly to permit the lever to pass the shoulder, a leaf spring 117being provided for pressing the latch member 113 inwardly so that theshoulder 116 will spring into locking engagement with the lover 110 assoon as the lever has been moved below the shoulder 116. The forward endof the latch member 113 lies alongside and above the treadle 112 so thatwhen the operator desires to return the printing cylinder to printingposition, the latch may be released by exerting lateral pressure thereonwith the foot engaging the treadle 112 with which the latch is engaged.

In connection with the means for disengaging the form cylinder from thework, means is also provided for simultaneously shifting the inkingmechanism to an inoper} ative posit-ion. The shifting means for theinking mechanism is operated by arms 118 fixed to the shaft 107 at theends thereof and links 119 extending upwardly and rearwardly from thearms 118 outside the standards 4. As best shown in Fig. 7, the rear endsof the links 119 are attached to short arms 120 which are fixed to theopposite ends of a transverse shaft121 which is journaled at its ends inthe brackets 42. Fixed to the shaft 121 adjacent the inner sides of thebrackets 42 are eccentric discs 122 which serve as cams for shifting thecarriage 41 rearwardly in opposition to the springs 46. r

The eccentric discs or cams 122 engage with rollers 123 mounted on atransverse shaft 124 which is supported at its ends in eccentricbushings 125 which are journaled in bearing brackets 126 secured to thecarriage 41, as shown in Fig. 8. l/Vhen the shaft 107 is rocked by theoperation of either of the levers 110 to lift the form cylinder, thearms 118 swing forwardly and shift the lin \IS 119 rearwardly rockingthe shaft 121 in the direction to apply pressure .to the rollers 123engaged by the cams 122,

shifting the carriage 41 rearwardly a sufficient distance to separatethe inkingroller 53 from the form cylinder so that the inking of theform cylinder is discontinued.

lifeans is provided for shifting the inking mechanism independently ofthe form eylinder so that the inking of the form cylinder may bediscontinued without moving the form cylinder from printing position. Tothis end, the shaft 124 has fixed thereto adj acent one end a hand lever127 bymeans of which the shaft 124 may be turned to rotate the bushings125 in the bearingbrackets 126 to move the shaft 124 bodily with respectto the brackets 126. The engagement of the rollers 123 with the cams 122holds the shaft 124 at a fixed distance from the shaft 121 and theadjustment of the bushing causes rearward movement of the bearingbracket 126 and of the carriage 41 to which it is attached. Adjacent theopposite end of the shaft 124 to which the hand lever 127 is at tached,there is a second lever 128 to which is connected an actuating rod 129which extends forwardly past the end of the form cylinder through aguide bracket 130 attached to the forward edge of the guide standard 4,the rod 129 being provided at its forward end with a handle 131 so thatan operator standing at the front end of the machine may shift theinking mechanism to an inoperative position by pulling forwardly on therod 129.

Chain guides In order to obtain a uniform feed of the sheet between theprinting cylinders without slippage between the sheet and form, it ishighly desirable that the conveying chains be accurately alined withrespect to the printing cylinders and in order to maintain thisalinement, adjustable guides are provided for the conveyor chainsrearwardly of the cylinders, see Figs. 21 and 22. The conveyor chains 5are cemposed of relatively short links connected by pivots 132 andtravel beneath upper guide bars 133 which are carried by the inwardlyprojecting flanges of angle bars 134 which are mounted along oppositeside edges of the table. The upper guide bars 133 are adjustablysupported beneath the flanges of the angle bars 134 by means of screws135. The chains 5 are held in close proximity to the guide bars 134 bymeans of lower guide bars 136 which are spaced beneath the bars 134, adistance but slightly greater than the thickness of the chains. Theguide bars 136 are supported by bolts 137 which extend through the guidebars, through spacing collars 138 located between angle brackets 139 andwhich are threaded into a supporting bar 140 adjustably mounted on thebrackets 139. The angle brackets 139 are fixed to the table framebeneath the guide bars and the supporting bars 140 are secured to theangle bars 139 by bolts 141. The openings in the angle brackets 139'through which the bolts 141 pass are slightly larger than the bolts soas to permit a slight vertical adjustment of the bar 140 and the bar 140is engaged at spaced points along its lower edge by the upper ends ofvertically disposed adjusting screws 142 which are mounted in anglecross bars 143 extending across the frame beneath the guides, the anglecross bars 143 serving also as supports for the angle brackets 139.

By adjusting the guide bars 133 and 136, the grippers may be maintainedin accurate alinement with the bight of the printing cylinders andfirmly held against vertical movement during the feeding of the sheetbetween the printing cylinders.

Stop dem'ee In order to enable the machine to operate continuously andat a relatively rapid rate, means is provided for positioning sheets tobe fed between the cylinders, and this means is in the form of a stopdevice immediately in front of the cylinders which is automaticallyreleased upon engagement of the grippers with the sheet, and which isautomatically restored to the operative position after a sheet being fedthrough the cylinders has been moved to a position clear of the stop,see Figs. 11 to 14, inclusive. Extending transversely across the tableat the forward end thereof and above the conveyor chains, there is atransverse shaft 144 to which are attached a series of collars 145 whichare held in adjusted positions on the shaft by means of set'screws 146.One of the collars 145 has a rearwardly and downwardly extending arm 147which has at its lower end a forwardly extending guide portion 148. Theguide portion 148 has slidably mounted on the under side thereof a stopblock 149 which may be adjusted forwardly or rearwardly by means of ascrew 150. The collars 145 have downwardly extending arms 151 to whichare attached spring guide aprons 152 in advance of the block 149 whichserve to guide the edge of the sheet to the proper position to beengaged by the grippers. The arms 147 are movable from a position inwhich the stop block 149 is in the path of movement of a sheet being fedto the machine to a position in which the stop block and aprons areentirely clear of the sheet so that the sheet may be advanced betweenthe printing cylinders.

Collars 145a near opposite ends of the shaft 144 are each provided witha pair of V-shaped notches 153 and 154 and these notches are engaged bybeveled detents 155 carried on the forward end of spring arms 156attached to brackets 157 attached to the stands 4. The spring actuateddetents 155 serve to yieldably retain the stop members either in theiroperative or inoperative position.

The stop and apron carrying arms 147 and 151 are so disposed withrespect to the axis of the shaft 145 that they normally swing tostopping position when released. Adjacent one end thereof, the shaft 144has attached thereto a trip arm 158 which is angularly adjustable uponthe shaft and which may be secured in adjusted position thereon by meansof a set screw 159. The trip arm extends rearwardly and upwardly fromthe shaft 144 with its inner end lying to the inner side of theperipheral portion of one of the gears 16 and is in the path of movementof a lug 160 which is adjustably attached to the gear. The lug 160 isformed in two parts connected by a clamping bolt 161 which serves tosecure the lug upon an annular T-shaped rib 162 projecting in- Adjacentthe arm 158, a rearwardly and J downwardl' extendin arm 163 is slidablkeyed to a collar on the shaft and may be adjusted by means of a bolt164 and a slot 165. At its lower end the arm 163 carries a roller 166which is engaged by a cam memher 167 which is an extension of one of theend plates 168 by which the gripper devices are attached to the chains5. The cam 167 swings the arm 163 upwardly, causing the stop arms 147 tobe swung upwardly to their inoperative position, in which position thedetents enter the notches and retain the stop members in elevatedposition until they are again released by the lug 169. The spacing ofthe grippers on the conveyor chains is exactly equal to thecircumference of the printing cylinder and the lug is so positioned onthe gear 16 that it will not engage with the trip arm 158 until after asheet being fed between the cylinders has passed to a position entirelyclear of the stop members. The size of the sheets printed upon may be ofvarious len ths and the sheets of shorter length will pass to a positionclear of the stop members sooner than the sheets of longer length. Inoperating upon shorter sheets, the stop may be adjusted to return thestop members to operative position after a shorter interval of time sothat a longer interval is permitted for the feeding of sheets from theroller table 7 into engagement with the stop.

Gripper ale vices As best shown in Figs. 14 to 18 inclusive. each cf thegripper devices, by means of which the sheets are drawn through thespace between the printing cylinders, is carried by means of the plates168, which are secured to laterally alined links of the end less chains5. The plates 168 are rigidly connected adjacent their forward ends bymeans of a cross bar 169 which is substantially rectangular in crosssection, the upper edge 170 of the bar 169 lying substantially inhorizontal plane tangent to the cylindrical surface of the form 20during its travel along the upper run of the chain.

Intermediate the ends of the plates 168 there is mounted a cross shaft171 which journaled in the plates and which carries gripper arms 172which have fingers 173 which are adapted to engage the top face 170 ofthe bar 169, the sheet being printed upon being firmly gripped betweenthe tingers 173 and the cross bar 169 during the passage of the sheetbetween the cylinders. The plates 168 are connected adjacent their rearends by cross shaft 174. A supporting memher 175 is supported on theshafts 171 and 174 adjacent the opposite ends thereof immediately to theinner sides of the end plates 168, and these members support shortshafts 176 immediately beneath the shaft 171. The shaft 171 has fixedthereto spur gears 177 which mesh with sp r gears 178 mounted on theshort shafts 176.

The shaft 174 has downwardly extending arms 179 pivoted thereto and thelower end of each of these arms is connected by a link 180 to an arm 181fixed to one of the gears 178, link 180 being connected to the arm 181by means of a pivot pin 182. A rod 183 is pivotally connected at itsrear end to the arm 179 intermediate the ends of the arm, and extendsforwardly between the shafts 171 and 176, the rod 183 being connected tothe arm 179 by the pivot 184 and being guided in an aperture 185 in theplate 186 which is secured to the cross bar 169 by means of bolts 187.The free end of the rod 183 is threaded to receive stop and lock nuts188 and 189.

A washer 190 is positioned against the inner face of the nut 188 and acompression coil spring 191 is interposed between the washer 190 and theguide plate 186. The spring 191 tends to move the arm 179 forwardly andthrough the link 180 to impart a turning movement to the gear 178 in onedirection or the other, depending on whether the pivot 182 is above orbelow its dead center position. The spring 191 thus serves to hold thegripper arms 172 either in their gripping position or in an inoperativeposition, the gripper arms being held in inoperative position when thepivot pin 182 is above dead center, as shown in Fig. 15 of the drawings.

The angular movement of the gears 178 is limited by means of stopshoulders 192 and 193 on the member 175, which are engaged by a lug 194as shown in Fig. 16, the move ment of the gears 178 being suiiicient toshift the gripper arms from their gripping position to an inoperativeposition rearwardly of the shaft 171. In order to shift the pivot 182 ineither direction past its dead center position, cams 195 are fixed tothe outer ends of the shafts 17 6 and each of these cams is providedwith a diametrical groove 196 which engages with trip rollers 197 and198 fixed to the side members of the table. The trip rollers 197 arepositioned beneath the stop mechanism at the forward end of the table,andthe rollers 198 are positioned adjacent the rear end of the table,the rollers 197 serving to actuate the grippers to cause them to swinginto engagement with the rear edge of a sheet resting on the cross bar169, and the trip rollers 198 serving to disengage the grippers from thesheet in the rear end of the table III to permit the sheets to beremoved from the table.

The spacing of the grippers on the chains is exactly equal to thecircumference of the form cylinder so that tie forward end of each sheetalways engages with the same portion of the form. In passing from theforward end of the upper run of the chains toward the printingcylinders, the upper face 170 of the cross bar 169 lies immediatelybeneath a sheet which is positioned on the table with its forward edgein engagement with the stop blocks 149 and the trip rollers 197 are sopositioned with respect to the stop blocks that the gripper arms arebrought into gripping position at the instant when the rear edge of thesheet lies upon the top face 170 of the gripper bar, the earn 167 beingso positioned as to simultaneously sweep the stop arms out of the pathof the sheet.

It is desirable that sagging of the sheet between the grippers and thecylinders be prevented since this would tend to cause relative slidingbetween the surface of the sheet and the surface of the form. Means istherewith the bars at their rear ends. The springs 200 provide numerouspoints of support for the sheet being printed upon by the grippers andcylinders and these springs are also adapted to yield to permit passageof the gripper carrying crossbars, the springs being flattened by thecross bars as they pass over them and springing back to supportingposition after the grippers have passed.

Operation tion of the fabric backing 21 is then secured to the squareshaft 28, whereupon the form is drawn into snug engagement throughoutthe periphery of the cylinder by turning the shaft 23 to wind the fabric21 thereon. The

form is thus caused to snugly engage the surface of the cylinderthroughout the circumference thereof so that a smooth cylindricalprinting surface is provided. After the form is attached, the bearingsof the form cylinder are adjusted to provide the desired pressureagainst the compression cylinder. The driving motor is then started inoperation to operate the cylinders and conveyor chains and a sheet to beprinted upon is placed upon the roller table 7 and pushed intoengagement with the stop block 149 which should be adjusted to cause thesheet to properly register with the form.

While the sheet is in this position, one of the gripper devices will becarried over the front sprockets 26 and will pass rearwardly beneath thesheet. When the cross bar 169 comes beneath the rear edge of the sheetwhich is in engagement with the stop block 149, the cam 167 will engagewith the roller 166, lifting the arm 16?) and turning the rock shaft 149to swing the stop carrying arm 147 to a position clear of the sheet. Atthe same time the cams 195 will engage with the trip rollers 197,causing the toggle pivot 182 to be moved downwardly past its dead centerposition, whereupon the spring 191 will act through the toggle andthrough the gears 178 and 177 to swing the gripper arms 172 intoengagement with the rear edge of the sheet resting on the top face 170of the cross bar 169.

As the gripper device is moved forwardly, it enters the recesses 9 and19 of the printing cylinders and one end of the form is brought intoengagement with the end of the sheet. Since the sheet is moving at alinear speed equal to the peripheral speed of the form cylinder, thesurface of the form will roll without slippage on the surface of a sheetand the raised portion of the form will transfer a coating of ink orpaint to the sheet while the portions of the sheet registering with thedepressed portions of the form receive no coating.

As the gripper passes over portions of the table at the rear of thecylinders, it will press down the successive arched springs 200 whichimmediately after the gripper has passed will spring back to theiroriginal position and provide supports for the sheet in the plane of thebight of the cylinder so that the sheet will not sag between the gripperand t 1e cylinders. After the forward end of the sheet has passed thestop device 10, the lug 168 on the gear 16 will strike the arm 168,rocking the same downwardly and imparting a corresponding movement totheshaft 144 and stop arms 147 to a position in which the stop blocks 149are in the path of a sheet fed toward the cylinders over the feed table.The yielding latches 155 cooperating with the notches 153 and 154 serveto yieldingly hold the rock shaft in the position to which it is movedby the cam 167 or in the position in which it is moved by the lug 160.After the stop arms are returned to operative posi tion, the operatorpushes a second sheet into engagement with the stops ready to be engagedby the next gripper. At the rear end of the machine 'thev camsil engagewith .V

'-11'1 3Cll&I11SII1 without lifting the .form:cylinder,xi this may bedone by pulling forwardly on then trip rollerstl98 which l act .to: rockthe toggle pivot-182:.toa position: above-its dead center, swinging,the: gripper arms x172rearwardly;

to release the ',sheet.-" After the EOgglGfiPlVOlJ over thelower run tothe forwardend of, the machine;

The machinerof the present invention may, beiemploycd to print uponsheets which vary considerably in length, and: in" printing upon shortersheets the stop arms may be. adv'anta geously returned to operativeposition sooner.

than with longer sheets, giving the-operator more" time in: whichtoposition the .nextzsheet. against the stops. This may beaccomplished'by adjusting the stop lug 160 along. its supporting rib 162-to providexashorterarci of travel forthe'form cylinder during the inter.-

144' by the cam 167' a-nd the actuation thereof by the lug 160. 3

In order to provide accurate registry be-" tween the form and sheet,th'eform cylinder may be adjusted bodily by-loosening the bolts 17' andturning the cylinder" with respect to: the gear any desired amountwithin the lim-z its-permitted by the slotsl8l If this adjust ment ofthe form cylinder does not cause the form and sheet to register'with'sufiicient ac curacy, final adjustments maybewmade byadjusting th'estopblock 149-bp means of' the screw 150.

It'is desirablethat the path of travel of the gripper beaccuratelyalined with the bight of the cylinders and to enable the pathof travel of the grippers to be adjusted to corre-" spond to differentadjustments of the fo'rm' cylinder and different thicknesses of formsmounted thereon, the guides 133 and 136'between which the chain travelsmay be'accu rately' adjusted by means of'th'e"screws135l and 142.

If at any time during the passage of a sheet between the cylinders it isfound :that the printing is not satisfactory, the form -cylinder may beinstantly shifted out of contact with the sheet by stepping onone of thetreadles 112 at the front of the machine whereupon the cylinder will'belifted 'to position clear of the sheet and will be re-- tained in thisposition by'the latches 113. At the same time the inking mechanism willbe shifted rearwardly by the actuation of the link 119 and cams 122 sothat theinking of regulated at any time during the operation of themachine by adjusting'the rollers 61 and 7O bymeansof-the screws58 and67. If, at

' the 1 front of the machine. 5 has been moved above dead, center-thespring 191E serves to: retain .thetgripperxarms in the: open position:while: the; chains are passing the particular form of apparatus shownand any time it is desired to disengage the linking actuatingrod130which liasa handle1311 atz":

It will be readily understood that the print-11w ing may be'doneiupon a.plainsheet or upon'a sheet which has previously beenprinted in a numberofdifi erenticolorsx such cylinders may be adjusted sothat 'o'ne'y formricylinder registers with :the printing done by. the preceding form.cylindern A In e :this way, a multi'ecolor sign maybe printed in 1 onepass. i

It will be apparent that the" present'invenlyprinting upon sheets havinga largesur face area. that the sheetpositioning, support-f ing andfeeding means enable the'sheets'tocbe accurately registered with theform and to.

between the surface of therform'and the-sum face of the sheet; the sheetbeing supported=at i all times throughout its length in'a plane ofcontact'between the form cylinder and sheets Furthermora'it'is to beunderstood-that described; and the particular procedurenset' 1 forth,are presented'for purposes'of explanaa -tion and illustration andthatyariousnmdi- "fications'of said a'pparatusand procedurecan 10 bemade without dep arting from" 'my inven tionas defined in theap-pendedclaims:

What I claim is:

1. A printingpress including a form cyliiis der and a compressioncylinder, a feed table over'which sheetsmay be advanced toward thecylinders, a stop device in front of the" bight'of the cylinders movableinto and outof a position in the path of a sheetbeing moved toward thecylinders, grippers mounted for movement'in a straightline through? thebight of the cylinders, means for auto-' matically actuating thegrippers to" grip a sheet positionedby the stop deviceand for"simultaneously shifting the stop deviceto a position clear of the sheet,means forretaining the stop device in inoperativeposition," andindependent means for returning the stop device to sheetengagingposition after the sheet engaged by the grippershas-been" moved to aposition clear of'the' stop device: #130? 85M, *tion provides a machinecapableof accurate-x val between the actuation- :of the 1 rock. shaft90. be fed between the cylinderswithout slippage the properadjustmentstobe made to provide for accurate registry betweenthesheetand form;

member moving with the grippers for shif ing the stop device to aposition clear of the sheet, means for automatically actuating thegrippers to grip thesheet, means for retaining the stop device in aninoperative position during passage of a sheet, and means forautomatically returning the stop device to operative position after thesheet engaged by the grippers has been moved past the stop. device.

3. A printing pressincluding a form cylinder and a compression cylinder,a feed table over, which sheets may be advanced toward the cylinders, astop device in front of the bight of the cylinders movable into and outof a position in the path of a sheet being moved toward the cylinders,grippers mount ed for movement in a straight line through the bight ofthe cylinders, means including a member moving with the grippers forshifting the stop device to a position clearof the sheet, means forautomatically actuating the grippers to grip the sheet, means forretaining the stop device in an inoperative position during passage of asheet, and means including a member rotating with one of said cylindersfor automatically returning the stop device to operative position.

4. A printing press including a form cylinder and a compressioncylinder, a feed table over which sheets may be advanced toward thecylinders, a stop device in front of the bight of the cylinders movableinto and out of a position in the path of a sheet being moved toward thecylinders, grippers mounted for movement in a straight line through thebightof the cylinders,means including a member moving with the grippersfor shifting the stop device to a position clear of the sheet, means forautomatically actuating the grippers to grip the sheet, means forretaining the stop device in an inoperative position during passage of asheet, and means includ' ing a member rotating with one of saidcylindersfor automatically returning the stop device to operative position, saidmember being ad ustabIe angularly with respect to the axis of thecylinder to vary the time during which the stop device is held ininoperative position. i

5. A printing press including a form cylin der and a compressioncylinder, a feed table over which sheets may be advanced toward thecylinders, a rock shaft extending across the table, stop arms fixed tosaid shaft and movable into and out of a position in the path of a sheetbeing advanced toward the cylinders, grippers mounted for movement in astraight line through the bight of the cylinders, means for moving saidgrippers at a lineal speed equal to the peripheral speed of the formcylinder, means including a stationary trip for automatically actuatingthe grippers to grip a sheet, a cam moving with the grippers andengaging an arm fixed to said rock shaft for actuating the rock shaft to1 the cylinders, a rock shaft extending across the table, stop armsfixed to said shaft, and

movable into and out of a position in the path of a sheet being advancedtoward the cylinders, grippers mounted for movement in a straight linethrough the bight of the cylinders, means for moving said grippers at alineal speed equal to the peripheral speed of the form cylinder, meansincluding a sta- 'tionary trip for automatically actuating the grippersto grip a sheet, a cam moving with the grippers, a trip lug mounted forrotation with one of said cylinders, arms fixed to the rock shaft andengageable with the cam and trip lug, and a latch for yieldinglyretaining the rock shaft in a position in which the stop arms are in thepath of a sheet and in a position in which the arms are clear of asheet.

7. A. printing press comprising a formcylinder, a compression cylinderupon which the form cylinder bears, a feed table over which sheets maybe advanced toward the cylinders, a stop device in front of the bight ofthe cylinders for positioning a sheet to be printed upon, grippersmounted for movement in a straight line beneath a sheet positioned inengagement with the stop device and rearwa-rdly through the bight ofsaid cylinder, means for automatically shifting the stop device to aposition clear of the sheet and for simultaneously engaging the gripperswith the rear end of the sheet, means for retaining the stop device inan inoperative position during passage of the sheet, and means forautomatically returning the stop device to operative position after thesheet engaged by the grippers has been moved past the stop device.

8. A printing press comprising a form cylinder, a compression cylinderupon whichthe form cylinder bears, intermeshing gears fixed to the twocylinders, a feed table over which sheets are advanced toward thecylinders, a rock shaft extending across the table in front of thecylinders, stop arms fixed to said shaft, a latch for yieldingly holdingsaid rock shaft in either of two positions, in one of which the stoparms are in the path of a sheet and in the other of which the stop armsare clear of the sheet, a cam for actuating said rock shaft between thecylinders.

9. A printing press comprising a form cyl-.

inder, a compression cylinder upon which the form cylinder bears,horizontal guides extending past opposite ends of the cylinders at thelevel of the bight thereof, members mounted for travel in said guides,means for moving said members at the peripheral speed of the formcylinder, a cross bar supported at its ends by said members and having atop face in the plane of the bight of the cylinders, a rock shaftparallel with said cross bar rearwardly thereof and supported in saidtraveling members, gripper arms fixed to said shaft and movable from aposition below the plane of the top surface of the cross bar to aposition in which they overlie said surface, means including a togglemounted beyond the ends of the cylinders for actuating said shaft, aspring connected to the toggle for actuating the same in eitherdirection from a dead center position, means in front of the cylindersfor positioning a sheet for engagement by the grippers, and meansincluding trip members attached to the guides adjacent the positioningmeans for shifting the pivot of the toggle past its dead center positionto cause said arms to be moved to sheet gripping position.

10. A printing press comprising a form cylinder, a compression cylinderupon which the form cylinder bears, horizontal guides extending pastopposite ends of the cylinders at the level of the bight thereof,members mounted for travel in said guides, means for moving said membersat the peripheral speed of the form cylinder, a cross bar supported atits ends by said members and having a top face in the plane of the bightof the cylinders, a rock shaft parallel with said cross bar rear-,wardly thereof and supported in said traveling members, gripper armsfixed to said shaft and movable from a position below the plane of thetop surface of the cross bar to a position in which they overlie saidsurface, gears fixed :to said rock shaft adjacent the ends thereof,

short shafts beneath said gears, gears fixed to the short shaftsandmeshing with the first mentioned gears, arms fixed to the short shaft,actuating arms pivoted rearwardly of the rock shaft, links connectingsaid arms to said arms fixed to the short shaft, actuating springsconnected to said actuating arms, cams fixed to the short shaft, andlugs on said guides engageable with said cams.

11. A printing press comprising a form cylinder and a compressioncylinder, endless chains mounted beyond the ends of said cylinders,horizontal guides for said chains extending past the ends of saidcylinders for supporting the same at the-level of the bight of thecylinders," vertically adjustable sup-c portsfor said guides at spacedpoints along the length thereof,means for driving said i cylinders andchains with the chains moving at a lineal speed equal to the peripheralspeed of the form cylinder, a cross member carried by 'the chains, andgrippers carried by said cross member.

12. A printing press comprising a form cylinder and a compressioncylinder having longitudinal recesses in their peripheries whichregister at the bight of the cylinders, endless chains mounted beyondthe ends of the cylinders and having gripper carrying cross memberswhich are received in the re- I cesses of the cylinders, and asupporting table at the rear of said cylinders having supportpermitpassage of the'cross cylinder and a compression cylinder havinglongitudinal recesses in their peripheries which register at the bightof the cylinders, endless chains mountedbeyondthe ends ofthe cylindersand having gripper carrying cross members which are received in therecesses of the cylinders, a supportingtable at the rear of saidcylinders having its surface below said cross members, and sheetsupporting members in the form of upwardly arched springs having theirforward ends attached to the table and their rear ends slidable on thetable.

14. A printing press comprising a supporting frame, form and compressioncylinders mounted one above the other in the frame, a feed table overwhich sheets may be advanced toward the cylinders, a stop memberextending across the table parallel with the cylin- I a sheet on thefeed table and in an inoperative position in which it is clear of thesheet, means for feeding sheets one at a time from said table throughthe bight of the cylinders, means movablewith said feeding means forengaging the stop member and shifting the same to inoperativepositiomand means movable with a cylinder for engaging the stop memberand shifting the same to operative position.

15. A printing press comprising a supporting frame, form and compressioncylinders mounted one above the other in the frame, a feed table overwhich sheets may be advanced toward the cylinders, a stop memberextending across the table parallel with the cylinders and movablymounted in the frame adjacent the bight of the cylinders, said stopmember'having a portion adapted to extend across the plane of a sheet onthe feed table to limit the movement of the sheet toward the cylindersand a portion adapted to overlie the sheet adjacent its rear edge toprevent upward movement of the edge of the sheet, means for releasablyholding the stop device in an operative position in which it is in thepath of a sheet on the feed table and in an inoperative position inwhich it is clear of the sheet, means for feeding sheets one at a timefrom said table through the bight of the cylinders, means movable withsaid feeding means for engaging the stop member and shifting the sametoinoperative position, and means movable with a cylinder for engagingthe stop member and shifting the same to 0p erative position.

16. A printin press comprising a supporting frame, form and compressioncylinders mounted one above the other in the frame, a feed conveyorhaving a straight run at the level of the bight of the cylinders andhaving sheet gripping means thereon which pass betwen the cylinders, afeed table for supporting a sheet adjacent the conveyor to the front ofcylinders, a stop device movably mounted in the frame to the front ofthe cylinders, means for holding the stop device in the path of a sheeton the feed table and for holding the same in a position clear of thetable, means controlled by the moving conveyor for shifting the stopdevice to inoperative position and for simultaneously moving thegripping means into gripping engagement with the edge of the sheetpositioned by the stop device, and means for automatically returning thestop device to operative position after a sheet engaged by the grippershas been moved to a position clear of the stop device.

17. A printing press comprising a supporting frame, form and compressioncylinders mounted one above the other in the frame, a feed conveyorhaving a straight run at the level of the bight of the cylinders andhaving sheet gripping means thereon which pass between the cylinders.a-feed table for supporting a sheet adjacent the conveyor to the frontof cylinders, a stop device movably mounted in the frame to the front ofthe cylinders, means for holding the stop device in the path of a sheeton the feed table and for holding the same in a position clear of thetable, means controlled by the moving conveyor for shifting the stopdevice to inoperative position and for simultaneously moving thegripping means into gripping engagement with the edge of the sheetpositioned. by the stop device, and means controlled by a rotatingcylinder for automatically restoring the stop device to operativeposition.

18. A printing press comprising a supporting frame, form and compressioncylinders mounted one above the other in the frame, a feed conveyorhaving a straight run at the level of the bight of the cylinders andhaving sheet gripping means thereon which pass between the cylinders, afeed table for su ortin a sheet ad'acent the conveyor to 7 PP g l thefront of cylinders, a stop device movably mounted in the frame to thefront of the cylinders, said stop device having a portion in the path ofthe rear edge of a sheet on the table to limit the movement of the sheettoward the cylinders and a portion adapted to overlie the sheet adjacentits forward edge to prevent upward movement of theedge of the sheet,means for holding the stop device in the path of a sheet on the feedtableand' for holding the same in a position clear of the table, meanscontrolled by the moving conveyor for shifting the stop device toinoperative position and for simultaneously moving the gripping meansinto gripping. engagement with the edge of the sheet positioned by thestop device, and means for auto1natically returning the stop device tooperative position after a sheet engaged by the grippers has been movedto a position clear of the stop device. 7

19. A printing press comprising a supporting frame, form and compressioncylinders mounted one above the other in the frame, said cylindershaving longitudinal peripheral recesses adapted to register duringrotation of the cylinders, an endless feed conveyor mounted on saidframe and having a horizontal upper run at the level of the bight of thecylinders and extending past the same, said conveyor comprising twoendless chains mounted beyond the opposite ends of the cylinders andcross members connected at opposite ends to the chains, means fordriving said cylinders at equal peripheral speeds and for driving saidfeed conveyor at a speed equal to the peripheral speed of the cylinders,a feed table for supporting a sheet above the conveyor adjacent thebight of the cylinders, a stop device movably mounted on the frame infront of the cylinders and having a portion extending into the path of asheet on the table, grippers on said cross members, means controlled bythe movement of the conveyor to actuate said grippers to grip the rearedge of a sheet in the position in which it is held by the stop deviceand for simultaneously shifting the stop device out of the path of thesheet, means for retaining the stop device in inoperative position, andmeans for automatically returning said stop device to sheet engagingposition after a predetermined movement of the feed conveyor. g

20. A printing press comprising a supporting frame, form and compressioncylinders mounted one above the other in the frame, said cylindershaving longitudinal peripheral recesses adapted to register duringrotation of the cylinders, an endless feed conveyor mounted on saidframe and having a horizontal upper run atthe level of the bight of thecylinders and extending past the same, said conveyor comprising twoendless chains mounted beyond the opposite ends of the cylinders andcross members connected at opposite ends to the chains, means fordriving said cylinders at equal peripheral speeds and for driving saidfeed conveyor at a speed equal to the peripheral speed of the cylinders,a feed table for supporting a sheet above the conveyor adjacent thebight of the cylinders, a horizontal rock shaft mounted in the frame infront of the cylinders and above the conveyor, stop arms carried by therock shaft, means including a yielding detent for holding said rockshaft in a position in which the stop arms project into the path of asheet on the feed table and for holding the shaft in a position in Whichthe stop arms are clear of the sheet, grippers carried by said crossmembers, means carried by the conveyor for turning the rock shaft toshift the stop arms to inoperative position, means for automaticallyactuating the grippers to grip the edge of a sheet positioned by thestop members, and means for automatically returning said stop device tosheet engaging position after a predetermined movement of the feedconveyor.

In testimony whereof I afiix my signature.

SAMUEL J. MOLLET.

